Revendor github.com/Microsoft/hcsshim to v0.8.3

Signed-off-by: Justin Terry (VM) <juterry@microsoft.com>

vendor/github.com/Microsoft/hcsshim/internal/wclayer/exportlayer.go

@@ -1,14 +1,11 @@
 package wclayer
 
 import (
-	"io"
 	"io/ioutil"
 	"os"
-	"syscall"
 
 	"github.com/Microsoft/go-winio"
 	"github.com/Microsoft/hcsshim/internal/hcserror"
-	"github.com/Microsoft/hcsshim/internal/interop"
 	"github.com/sirupsen/logrus"
 )
 
@@ -44,96 +41,20 @@ type LayerReader interface {
 	Close() error
 }
 
-// FilterLayerReader provides an interface for extracting the contents of an on-disk layer.
-type FilterLayerReader struct {
-	context uintptr
-}
-
-// Next reads the next available file from a layer, ensuring that parent directories are always read
-// before child files and directories.
-//
-// Next returns the file's relative path, size, and basic file metadata. Read() should be used to
-// extract a Win32 backup stream with the remainder of the metadata and the data.
-func (r *FilterLayerReader) Next() (string, int64, *winio.FileBasicInfo, error) {
-	var fileNamep *uint16
-	fileInfo := &winio.FileBasicInfo{}
-	var deleted uint32
-	var fileSize int64
-	err := exportLayerNext(r.context, &fileNamep, fileInfo, &fileSize, &deleted)
-	if err != nil {
-		if err == syscall.ERROR_NO_MORE_FILES {
-			err = io.EOF
-		} else {
-			err = hcserror.New(err, "ExportLayerNext", "")
-		}
-		return "", 0, nil, err
-	}
-	fileName := interop.ConvertAndFreeCoTaskMemString(fileNamep)
-	if deleted != 0 {
-		fileInfo = nil
-	}
-	if fileName[0] == '\\' {
-		fileName = fileName[1:]
-	}
-	return fileName, fileSize, fileInfo, nil
-}
-
-// Read reads from the current file's Win32 backup stream.
-func (r *FilterLayerReader) Read(b []byte) (int, error) {
-	var bytesRead uint32
-	err := exportLayerRead(r.context, b, &bytesRead)
-	if err != nil {
-		return 0, hcserror.New(err, "ExportLayerRead", "")
-	}
-	if bytesRead == 0 {
-		return 0, io.EOF
-	}
-	return int(bytesRead), nil
-}
-
-// Close frees resources associated with the layer reader. It will return an
-// error if there was an error while reading the layer or of the layer was not
-// completely read.
-func (r *FilterLayerReader) Close() (err error) {
-	if r.context != 0 {
-		err = exportLayerEnd(r.context)
-		if err != nil {
-			err = hcserror.New(err, "ExportLayerEnd", "")
-		}
-		r.context = 0
-	}
-	return
-}
-
 // NewLayerReader returns a new layer reader for reading the contents of an on-disk layer.
 // The caller must have taken the SeBackupPrivilege privilege
 // to call this and any methods on the resulting LayerReader.
 func NewLayerReader(path string, parentLayerPaths []string) (LayerReader, error) {
-	if procExportLayerBegin.Find() != nil {
-		// The new layer reader is not available on this Windows build. Fall back to the
-		// legacy export code path.
-		exportPath, err := ioutil.TempDir("", "hcs")
-		if err != nil {
-			return nil, err
-		}
-		err = ExportLayer(path, exportPath, parentLayerPaths)
-		if err != nil {
-			os.RemoveAll(exportPath)
-			return nil, err
-		}
-		return &legacyLayerReaderWrapper{newLegacyLayerReader(exportPath)}, nil
-	}
-
-	layers, err := layerPathsToDescriptors(parentLayerPaths)
+	exportPath, err := ioutil.TempDir("", "hcs")
 	if err != nil {
 		return nil, err
 	}
-	r := &FilterLayerReader{}
-	err = exportLayerBegin(&stdDriverInfo, path, layers, &r.context)
+	err = ExportLayer(path, exportPath, parentLayerPaths)
 	if err != nil {
-		return nil, hcserror.New(err, "ExportLayerBegin", "")
+		os.RemoveAll(exportPath)
+		return nil, err
 	}
-	return r, err
+	return &legacyLayerReaderWrapper{newLegacyLayerReader(exportPath)}, nil
 }
 
 type legacyLayerReaderWrapper struct {